To understand changes in the faecal flora, one has to know the physiological flora first. The aim of this paper is to give insight into the changes of the culturable faecal flora of European brown hares (Lepus europaeus) in a captive setting. Therefore faecal samples were collected from three juvenile hares as soon as possible after birth until their death, and from two adult female hares for almost one year. Samples were collected once a week and further processed as soon as possible. A routine bacteriological investigation was performed, as well as selective isolation of III. generation cephalosporin-resistant and fluoroquinolone-resistant enterobacterial isolates. The juvenile hares showed a somewhat more variable flora, the adult hares a rather stable composition. Only seldom potential pathogenic bacteria (i.e. Escherichia coli and Clostridium perfringens) were isolated from the adult hares. These pathogens were found after moments of stress. The more variable flora in the juveniles is seen as a result of the not yet completely developed immune system, and due to the stress of weaning. One juvenile showed a severe shift of the flora due to a severe typhlocolitis. Our results give insight into the normal faecal flora of European brown hares. These results can act as baseline information and help interpreting results gathered in a clinical setting, as well as during field work. (C) 2016 The Authors. Published by Elsevier B.V.